Tag Archives: Cancer

When it comes to health care and medicine, nuclear science had made numerous accomplishments that have improved the lives of millions of people around the world. As Canada celebrates 150 years, we wanted to look back at some of our achievements.

In the late 1800s Dr. Harriet Brooks, Canada’s first nuclear physicist, discovered radon while at McGill University and worked in the lab of Dr. Marie Curie. Her work laid the foundation for nuclear physics and paved a pathway forward for women like Sylvia Fedoruk.

In the mid-1950s, Fedoruk and a team of researchers under the guidance of Dr. Harold Johns, became one of the first groups in Canada (the other was a team from London, Ontario) to successfully treat a cancer patient with cobalt-60 radiation therapy. Today, it is estimated that over 70 million people around the world have benefited from this treatment and cobalt-60 machines are still in use today.

The benefits and applications of cobalt-60 extend far beyond cancer treatments. The ability of cobalt-60 to effectively kill off even the tiniest of potentially harmful microbes makes it the perfect sterilization tool for medical equipment like gloves, gowns, IV bags, syringes and catheters. Medical-grade cobalt or High Specific Activity (HSA) cobalt-60, like the kind used by Feodurk and others, has been a foundation for cancer treatment for over 60 years. A recent partnership between Nordion and Bruce Power will ensure that cobalt-60 continues to be readily available for years to come.

Pioneers in medical isotopes over half a century ago, Canada led the world in the supply of isotopes, contributing to the betterment of global health. Used for the diagnosis and treatment of various diseases and illnesses such as imaging of the brain, lungs, heart and kidney, isotopes have been a key component to the health-care system have helped millions of people every year. The importance of isotopes is increasing. According to a recent report, the global market for nuclear diagnostic medicine is expected to double by 2020. Globally, over 40 million nuclear medicine procedures are performed every year.

Today, in the halls at TRIUMF in Vancouver, scientists are working on the next wave of cancer treatments through the exploration of alpha therapies. Through a targeted approach, cancer cells are blasted from the inside out, minimizing damage to healthy tissues. These alpha-emitting isotopes are thought to be especially effective for dealing with late-state or metastasized cancers (cancer that has spread from one part of the body to another).

In order to develop the necessary tools to diagnose and treat patients, an understanding of how our body functions at the cellular level is key. The community of St. Catharines, Ontario is home to Brock University. There groups of scientists are looking to unlock the answers to some of the world’s most pressing health challenges by figuring out how our body works by peering inside our cells. Using a neutron beam and a very high-resolution microscope, you can look inside the tissues of cells without doing any damage. Thad Harroun is an Associate Professor at Brock University. He came to Canada in 2003 to work at the Canadian Neutron Beam Centre and has worked on numerous experiments to better understand the interactions inside our bodies. One of his recent projects involves a better understanding of cholesterol.

“We want to know how proteins in our cells interact with cholesterol and fats and we are looking to see how cholesterol supports cell membranes,” he said.

Once thought to be the enemy of our arteries, new research has highlighted the importance of cholesterol to both cellular and lung health. Harroun’s work has also explored the importance of Vitamin E to cellular health.

Leading edge cancer treatments today include Gamma Knife Radiosurgery. Contrary to its name (the procedure isn’t surgery and doesn’t involve a knife) beams of radiation, two-hundred in total, converge on cancerous cells to more effectively kill tumors while protecting surrounding healthy tissues and provides new hope for those dealing with brain tumors and lesions.

Our history with nuclear medicine is a storied and varied. As Canada marks its 150th birthday there are many reasons to be proud of our many achievements that will continue to benefit the lives of people around the world for generations to come.

While Tragically Hip front man Gord Downie may be the most recognized person to be living with glioblastoma, brain cancer affects hundreds of thousands of families every year. A bleak diagnosis, the five-year survival rate for patients aged 45 to 54 sits at just four per cent according to the Canadian Cancer Society.

However, there is reason to be hopeful. New research in nuclear medicine targets cancers like glioblastoma through an inside-out approach, giving patients a new lease on life. These small and mighty cancer fighters are known as alpha-emitting isotopes and unlike traditional radiation therapy, which blasts cells from the outside, alphas attack cancer from the inside, protecting healthy tissues while destroying diseased ones.

“It’s a magic bullet for people in the cancer field because it has the beauty of sparing healthy tissues and finding and weeding out tiny tumors,” according to Dr. Tom Ruth, Special Advisor, Emeritus, TRIUMF.

Recently, The Medical University of Warsaw beat out over 2,000 other submissions to win the Marie Curie Award from the European Association of Nuclear Medicine (EANM) for their work on alpha therapies. Their research indicated that the work of alpha therapies could extend the life of patients with brain cancer by almost two years compared to patients who weren’t treated by alpha radiation. Alpha-emitting isotopes, unlike their beta radiation counterparts, have higher energy and can only travel short distances which makes them ideal cancer fighters.

“Alpha particles fly very short distances so because of short penetration range in tissues you won’t destroy healthy cells,” stated Valery Radchenko, Research Scientist, TRIUMF.

Researchers at TRIUMF are mapping out alpha-emitting isotopes as a way of extending the life of cancer patients or curing them all-together. Alpha-therapy is thought to be especially effective for those with late-stage or metastasized cancers (cancer that has spread from one part of the body to another).

“The key to alpha is to combine them with the right biomolecule to target the cancer cells. If you can find a way to get an alpha-emitting isotope to a tumor you can potentially cure the cancer,” said Radchenko.

While alpha-therapy could be a game changer in the fight against cancer, researchers need wider access to the alpha particles and closer partnerships with the health care system in order to complete the preliminary tests required to bring alpha-therapies to the mainstream market.

“The main problem is lack of facilities for the production of a clinically relevant amount of alpha emitters. There are just several around the world so they aren’t readily available,” stressed Radchenko.

In total, the nuclear medicine community relies on a wide suite of medical isotopes. There are approximately 200 isotopes available for use. Each isotope has its own characteristics and the ability to provide doctors with a window into what is happening inside the body.

An isotope known as fluorine-18 is attached to a tracer to make a radiopharmaceutical. It is then injected into the patient where it moves throughout the body depending on the tracer. In Canada, PET/CT scans use the radiopharmaceutical flurodeoxyglucose (FDG). Approximately 60 minutes after injection, the scanning part of the procedure begins.

“FDG is a sugar and the sugar is burned up by different parts of the body at different rates,” according to Dr. Neil Alexander, executive director of the Fedoruk Centre. “In nuclear medicine, particularly in diagnostics, if you have a sugar it goes around the body and anything burning up the sugar at a great rate lights up on the scan. As one example, cancer cells burn up sugar at a greater rate than healthy cells, allowing physicians to detect cancers and see how the disease responds to treatment.”

PET/CT scans provide doctors with vital information on the location and extent of cancer within the body. The test also allows doctors to assess the success of treatments; providing patients with a better chance at survival.

Parkinson’s disease diagnosis and research is one of the newest areas for medical isotopes and PET/CT. Early diagnosis in the case of Parkinson’s is an important step to increasing knowledge on how the disease progresses and responds to therapy. In the case of Parkinson’s patients the scan is looking for a decrease in proteins used in the synapses, or the junctions between nerve cells, in the brain.

Until the cyclotron started producing isotopes, patients requiring a scan in Saskatchewan needed isotopes flown in from Ontario and because the radioactivity is short-lived, meaning FDG cannot be stored, daily shipments were required. The challenges of early morning production added to air transportation often led to delayed starts and cancellations, providing unreliability for patients in need of medical diagnoses.

“Up until now, all of it was coming in from Hamilton and a lot of the material had decayed so they couldn’t process as many patients,” says Alexander.

Producing locally means more reliable health care for patients, cutting wait times and diagnosing more patients sooner. It also means that Saskatchewan medical researchers have a supply readily available to expand their research programs.

Cancer is very complex. Curing patients without causing side effects means that the treatments must be very targeted.

“Not all cancers are the same,” according to Dr. Michael Milosevic, a radiation oncologist at the Princess Margaret Cancer Center in Toronto. “Cancer is not one diagnosis. Each individual cancer is different.”

For patients diagnosed with cancer, surgery, radiation treatment and drug treatment (chemotherapy) are frequently used. External radiation, a beam targeted to a tumor that travels to the tumor from outside of the patient’s body comprises 80-90% of radiation therapies.

Brachytherapy, on the other hand, involves inserting the radiation into the center of the tumor and irradiating the cancer cells from the inside out. The treatment has proven successful in fighting prostate and cervical cancers.

“With brachytherapy, you can kill the cancer but spare the normal surrounding areas,” says Milosevic. “The likelihood of curing the cancer goes way up and the side effects way down.”

Temporary implants use special catheters inserted into the tumor. They connect to a machine to deliver the radiation treatments. A temporary implant is a day procedure. The radiation is delivered over a very short period of time, usually a few minutes, and then the catheters are removed.

Permanent implants directly insert small radioactive “seeds,” each about the size of a grain of rice, into the tumor. In the case of prostate cancer treatment, about 100 seeds are placed into the prostate gland, usually when the patient is asleep. The seeds remain in the prostate gland for the remainder of the patient’s life and give off a continuous flow of radiation that is highest immediately after insertion and declines to zero over a few months.

The uses for brachytherapy continue to develop. It has proven useful in treating some breast, head and neck cancers. Perhaps one of the biggest developments, as Dr. Milosevic points out, is the shift to magnetic resonance imaging (MRI). The Princess Margaret Cancer Centre is home to three MRI units that help to deliver brachytherapy.

“With Brachytherapy you put the radiation in the center of the tumor so you can kill the cancer but spare the normal surrounding areas. The likelihood of curing goes way up and side effects go down.”

Doctors are using medications that contain radioactive materials so they can get an inside look at how your body operates. Patients receive these radiopharmaceuticals by injection, or by inhaling or swallowing the medication.

As oncologist Sandy McEwan explains, “It circulates and binds at the site of the target and then we measure the distribution of the injection in space or time to understand what changes or functions are occurring.”

Dr. McEwan is a professor and chair of the department of oncology at the University of Alberta’s Cross Cancer Institute in Edmonton. He is also a member of the Canadian Nuclear Safety Commission, the independent nuclear regulator.

Dr. McEwan says advances in nuclear medicine are growing thanks to strong and active research and development.

The U.S. Food and Drug Administration (FDA) recently approved the use of radiopharmaceuticals to help evaluate patients for Alzheimer’s disease and dementia.

Advances are also being made in other areas such as cancer behaviours, according to Dr. McEwan.

“Tumors tend to use more glucose or sugar than regular cells,” Dr. McEwan says. “Using radiopharmaceuticals, doctors can measure how much glucose is being used by a tumor. The more sugar used by the cancerous cell, the worse the tumor is.”

These new medicines aren’t just used for diagnoses. Their very nature allows doctors to tailor them to individual patients.

“It’s personalized medicine,” says Dr. McEwan. “The right dose of the right drug, at the right time, for the right patient.”

By John StewartDirector, Policy and ResearchCanadian Nuclear Association

Blue-eyed John Stewart

Like many blue-eyed, middle-aged men who’ve been hiking, cycling, canoeing and kayaking since childhood, I have basal cell carcinoma, in the form of little low-grade cancerous spots on my skin.

Exposure to non-sun radiation is one of the main risk factors. It’s apparently #2 after too much sunshine – and not counting being blue-eyed, middle-aged, and male, none of which I can be expected to avoid, at least not at this point.

So how come the medical advice I get doesn’t say anything about avoiding licensed nuclear facilities? My doctors know what I do for a living, but none of them tell me to stay clear of Chalk River, Blind River, Kincardine, Port Hope, Darlington or Pickering.

Instead, the advice I get from them is 90% about hats, shirts, glasses and sunscreen (fair enough). About 5% is about avoiding tanning beds and sun lamps (no problem). About 3% is about staying in the shade (ha!). And the remaining 2% is about taking vitamin D so I won’t mind sitting in the shade for the rest of my life.

Why nothing about the nuclear industry? Because emissions from nuclear facilities are so low, they don’t matter.

The non-sun radiation sources that health care organizations talk about include anything other than nuclear power plants, including:

Cancer treatment itself (radiation to treat a first cancer might cause a second cancer)

Naturally occurring radon gas in my basement

Weapons testing programs that occurred before I was born.

Why nothing about the nuclear industry? Again: emissions from nuclear facilities are so low, they don’t matter.